class Solution {
public:
    int maxProfit(vector<int>& prices) {
        int buy = prices[0];
        int res = 0;
        for(int i = 1; i < prices.size(); i++)
        {
            if(prices[i] < buy)
                buy = prices[i];
            else
            {
                res = res + prices[i] - buy;
                buy = prices[i];
            }
        }

        return res;
    }
};